After some reflection Miss Amber Dextrous, determined to rule Cardiff's first Gay Wedding Show with a firm hand, decided on another outing for the ever reliable £300 full-length white sequins and flowers gown, and a belting version of I'm So Excited as an opener.

"It is all about weddings, has to be something big, white, a bit OTT. Actually completely OTT," said Paul Coombes, Miss Dextrous's alter ego. She moonlights as an agony aunt with a robust line, offering brutal advice to people whose partners have cooled on them.

"I think a lot of people come because they're just curious - gay weddings are still quite new, they may never have been to a partnership registration ceremony, they'll just want to see what's on offer. Straights, too."

Like most wedding fairs the show features firms offering clothes, flowers, catering, musicians, three-tier cakes, matching wedding rings including ones in stainless steel, or £499 platinum rings inscribed with vows such as "I take you to be my partner for life", photo albums - the £24.99 one with a folded paper sculpture of identical tuxedos has been a bestseller - cars, honeymoon travel agencies. There were no white meringue dresses, and also a few unusual features: legal advice on making wills, on funeral arrangements, and on how to make provisions for children often of earlier heterosexual relationships, on civil rights and equality legislation.

The honeymoon firms do not just feature couples walking arm in arm into the sunset, but advice on where not to go. Jamaica is emphatically not recommended, and several of the island's luxury resorts will not admit gay couples at all. Dubai, with guaranteed sand and sun, seemed an attractive option to one couple last year: they and eight members of their wedding party ended up in jail. Yesterday was the fourth Gay Wedding Show, and in an ideal world Gino Meriano, co-founder of a firm called Pink Weddings, thinks the fairs he started should not exist. "I don't want to be doing this, I'd rather be getting on with my gay rights campaigning. I'd stop tomorrow if I thought that society was now fully inclusive, and that gay couples could just go to any firm on the high street and be treated like any other couple - but it isn't, and they can't."

Their office, in demure Weybridge in Surrey, no longer has a high street shopfront, after previous premises in London were splattered with paint, potential customers were followed and jeered at or had their cars vandalised, and they themselves received vicious anonymous letters including death threats. His own father only learned of his wedding in the paper, and his partner's family has not accepted the relationship at all.

Pink Weddings' research suggests that up to a quarter of the conventional wedding market actively or tacitly discourages gay custom, anything from calls not returned to dropped jaws or stifled giggles if two men go into a high street jeweller to buy matching rings. "Most people, if they want to organise such a special day, don't want to have to start explaining their sex life. They just want all that to be taken for granted," Mr Meriano said.

There are some striking exceptions to this depressing rule. The show was sponsored by middle England's favourite corner shop, the John Lewis Partnership. "We have always catered for civil partnership celebrations," a spokeswoman said, "and have even noticed a significant increase in the number of same sex gift lists registered at John Lewis since civil partnerships became legal in December 2005."

Moss Bros, the formal dress hire company, has also embraced this market from the start, and the National Trust sought a meeting before the partnership legislation to assure Pink Weddings that it welcomes gay weddings in its properties.

Pink Weddings organised Mr Meriano's own partnership ceremony and celebration with Mike - who has taken his surname - on the day it became law, making them one of the first legally recognised gay couples in the country.

The party was full English breakfast at the Metropole in Brighton, with guests invited to bring Christmas decorations with special inscriptions, to decorate a towering tree.

They have organised weddings for others, with two aisles for two women both being given away by their fathers, with no aisle because no member of either family would come, and with beloved pets participating as Best Dog. Most of their couples are older, more assured and confident about what they want, but they've had people meekly ask if they're "allowed" a wedding cake.

Amber Dextrous spent the day cajoling, encouraging and reassuring couples towards the double rings and the registration book, but neither she nor Paul Coombes - a valleys boy astonished at how well Amber is received in miners' halls and working men's clubs in the small towns and villages of his childhood - has quite got there. "I think gay weddings are great, but like any wedding it is a really serious step. It's got to be the right person, and for me that just hasn't happened yet."

Trendwatch: Civil partnership ceremonies

The theme

Moroccan is the most popular. The full theme would include a bedouin tent, candle lanterns, belly dancers, chef and charcoal grill, floor cushions

From £5,000

The suits

Coordinating but non-identical designer suits for men, suit and non-meringue gown in any colour except white for women.

From £800 for two

The cake

Same sex cake topper figures sometimes modelled as caricature portraits of the couple